Extracellular fluid chloride

Small quantities of ionic chlorine are found in blood and milk. In extracellular fluid, chloride ions help to regulate the osmotic pressure, while in salivary amylase the chloride ion activates the starch-splitting enzyme of saliva. Free hydrochloric acid is found in the stomach as part of the mixture of digestive fluids. 

AletabolicFunctions. The chlorides are essential in the homeostatic processes maintaining fluid volume, osmotic pressure, and acid—base equihbria (11). Most chloride is present in body fluids a Htde is in bone salts. Chloride is the principal anion accompanying Na" in the extracellular fluid. Less than 15 wt % of the CF is associated with K" in the intracellular fluid. Chloride passively and freely diffuses between intra- and extracellular fluids through the cell membrane. If chloride diffuses freely, but most CF remains in the extracellular fluid, it follows that there is some restriction on the diffusion of phosphate. As of this writing (ca 1994), the nature of this restriction has not been conclusively estabUshed. There may be a transport device (60), or cell membranes may not be very permeable to phosphate ions minimising the loss of HPO from intracellular fluid (61). 

The extracellular fluid (ECF) is the fluid outside the cell and is rich in sodium, chloride, and bicarbonate. O The ECF is approximately one-third of TBW (14 L in a 70-kg man or 12 Lin a 70-kg woman) and is subdivided into two compartments the interstitial fluid and the intravascular fluid. The interstitial fluid (also known as lymphatic fluid) represents the fluid occupying the spaces between cells, and is about 25% of TBW (10.5 L in a 70-kg man or 8.8 L in a 70-kg woman). The intravascular fluid (also known as plasma) represents the fluid within the blood vessels and is about 8% of TBW (3.4 L in a 70-kg man or 2.8 L in a 70-kg woman). The ECF is approximately one-third of TBW or 14 L in a 70-kg male. Because the exact percentages are cumbersome to recall, many clinicians accept that the ECF represents roughly 20% of body weight (regardless of gender) with 15% in the interstitial space and 5% in the intravascular space.6 Note that serum electrolytes are routinely measured from the ECF. 

The basic answer to this question is that ions move across the plasma membrane of the neuron. Recall that ions are charged particles, frequently derived from single atoms by the gain or loss of electrons. The ions that are most important to us in understanding nervous system function are sodium ion, Na+, potassium ion, K+, calcium ion, Ca +, and chloride ion, Cl . If we compare the concentrations of these ions on the inside of the neuron and in the extracellular fluid that bathes the neuron, we find the neuron interior has a higher concentration of potassium ion than does the exterior fluid. In contrast, the exterior fluid has higher concentrations of sodium, calcium, and chloride ions than does the neuron interior. These concentration differences are referred to as concentration gradients. 

Calcium chloride-To combat severe hyperkalemia pending correction of increased potassium in the extracellular fluid. 

Sodium chloride (normal saline)- 0.9% Sodium chloride (normal saline), which is isotonic, restores both water and sodium chloride losses. Other indications for parenteral 0.9% saline include Diluting or dissolving drugs for IV, IM, or subcutaneous injection flushing of IV catheters extracellular fluid replacement treatment of metabolic alkalosis in the presence of fluid loss and mild sodium depletion as a priming solution in hemodialysis procedures and to initiate and terminate blood transfusions without hemolyzing red blood cells. 

Pharmacology Normal osmolarity of the extracellular fluid ranges between 280 to 300 mOsm/L it is primarily a function of sodium and its accompanying ions, chloride, and bicarbonate. Sodium chloride is the principal salt involved in maintenance of plasma tonicity. One gram of sodium chloride provides 17.1 mEg sodium and 17.1 mEq chloride. 

Mechanism of Action A thiazide-like diuretic and antihypertensive. As a diuretic, blocks reabsorption of sodium, potassium, and chloride at the distal convoluted tubule, increasing renal excretion of sodium and water. As an antihypertensive, reduces plasma and extracellular fluid volume and peripheral vascular resistance. Therapeutic Effect Promotes diuresis and reduces BP. 

Mecfianism of Action A loop diuretic that enhances excretion of sodium, chloride, potassium, and water at the ascending limb of the loop of Henle also reduces plasma and extracellular fluid volume. Therapeutic Effect Produces diuresis lowers BP. Pharmacokinetics ... 

It will be apparent that if normal extracellular fluids were subjected to an isotonic resorption of sodium and chloride ions by the process, the net effect would be to concentrate other ions and precipitate minerals. This suggestion was made613 to explain one of the methods of forming deposits in the calciferious glands of earthworms. It was proposed that the posterior glands received blood directly from the intestine. Fluid was formed in these glands by a process of filtration and saline was then resorbed by the epithelial cells. This resulted in the formation of calcareous deposits (Fig. 5). 

Chloride, a normal constituent of extracellular fluid in the body, is an important anion in the maintenance of fluid and electrolyte balance, as well as a necessary component of gastric juice. Whole milk contains 103 mg chloride per 100 g (NDC 1983A). 

For example, sodium ion is the principal cation of the extracellular fluid of the mammalian body, comprising, as the chloride and bicarbonate, more than 90% of the total solute in that fluid. Ingestion of sodium chloride solutions is used to replace salt lost by excessive perspiration. More sophisticated preparations have been proposed for this purpose one such preparation5 comprises mainly sodium chloride, supplemented with smaller amounts of potassium and phosphate ions to approximate the average composition of sweat in a sweetened glucose solution. 

The pH-buffering of extracellular fluid depends in part on the carbon dioxide/ bicarbonate equilibrium so that the intake of sodium bicarbonate is followed by a brief alkalosis and an increased excretion of sodium carbonate in the urine. Depending on its carbonate concentration, the pH of the urine may rise to 8.07. Large doses (80—100 g/day) of sodium bicarbonate were needed if the pH of stomach contents was to be maintained at 4 or over in patients with duodenal ulcers8. Oxidation of organic anions in the body to carbon dioxide and water permits the use of sodium citrate, lactate or tartrate instead of sodium bicarbonate. In an analogous manner the ingestion of ammonium chloride induces a brief acidosis as a result of the metabolic conversion of ammonia to urea and lowers the pH of the urine. 

The nerve cell membrane separates the external from the internal cell fluid, as does any cell membrane. As is true of virtually all cells, the intra- and extracellular fluids are electrolytic solutions of almost equal conductivity, but their chemical composition is very different. The ions present in largest quantities are sodium and potassium. The species in the external fluid are made up of more than 90 per cent sodium and chloride ions in the cell interior there are principally potassium and organic ions that cannot pass through the membrane, only 10 per cent of the ions being sodium and chloride. 

All cells, including muscle and nerve cells, have inside them an intracellular fluid (ICF) which contains high levels of potassium, K+, phosphate ions, PC>43+, and protein and small amounts of Na+ ions and chlorine ions. Outside the cells in the extracellular fluid (ECF) consists mostly of sodium ions, Na+, chloride, Cl, and bicarbonate ions, HC03, but no protein, plus low concentrations of potassium ions. The inner layer of the cell membrane is negatively charged relative to the outside. When activity occurs then an ionic pumping action takes place to try to maintain the balance within the cells between the intra and extra flow of sodium and potassium... 

Except for respiratory and dermal insensible water-vapor losses, all remaining water lost by the body contains electrolytes, mainly sodium and chloride. The normal cation and anion constituent composition of the fluid spaces is given in Table IV. In the extracellular fluid space, sodium is the major cation and chloride the major anion. Those two ions constitute 95 of the extracellular fluid osmolality. Changes in plasma sodium concentration reflect changes in extracellular fluid volume. Potassium is the major cellular cation and phosphates and proteins comprise the major anions. The total cellular osmolality (175 + 135 = 310 mosraol/kg H2O) is equal to the total extracellular osmolality (155 + 155 = 310 mosmol/kg HaO) therefore, equal total osmotic concentrations are maintained between two fluid compartments of widely different ionic contents (Table IV). 

The most common molecules in the body are water and inorganic molecules such as sodium, potassium and chloride ions. A feature that is common among all living cells is that the concentrations of these ions are different in the extracellular and intracellular compartments. The extracellular fluid is high in sodium (Na+) and chloride (CT) ions, but low in potassium (K" ) ions (Figure 10.1). In contrast, the intracellular solution is... 

The motor unit has four components a motor neuron in the brain or spinal cord, its axon and related axons that comprise the peripheral nerve, the neuromuscular junction, and all the muscle fibers activated by the neuron. Like other cells, nerve and muscle cells have an external membrane that separates the inner fluids from those on the outside. The fluid on the inside is rich in potassium (K), magnesium (Mg), and phosphorus (P), whereas the fluid on the outside contains sodium (Na), calcium (Ca), and chloride (Cl). When all is quiet, the internal chemical composition of both nerve and muscle cells is remarkably constant and is called resting membrane potential. A primary reason for this constancy lies in the cells ability to regulate the flow of sodium— thanks to an enzyme in the membrane called Na+/K+ ATP-ase. Because the inside of the cell has less sodium than the outside, there is a negative potential (like a microscopic battery) of 70-90 mV. Under ordinary circumstances, the interior of the cell is 30 times richer in potassium than the extracellular fluid and the sodium concentration is 10-12 times greater on the outside of the cell. At rest, sodium tends to flow into cells and potassium oozes out. 

The activities of ail enzymes and the three-dimensional conformations of all proteins and nucleic acids are sensitive to the overall concentration of ionic charges In the surrounding fluids. In extracellular fluids, the major cation is sodium. In intracellular fluids, the major cation is potassium. The major anions of biological fluids are chloride and phosphate. The general requirement of macrumolecules for anions and cations might be called a requirement for a medium having a specific... 

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